fs/nfs/super.c

   1 /*
   2  *  linux/fs/nfs/super.c
   3  *
   4  *  Copyright (C) 1992  Rick Sladkey
   5  *
   6  *  nfs superblock handling functions
   7  *
   8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
   9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
  10  *
  11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
  12  *  J.S.Peatfield@damtp.cam.ac.uk
  13  *
  14  *  Split from inode.c by David Howells <dhowells@redhat.com>
  15  *
  16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
  17  *   particular server are held in the same superblock
  18  * - NFS superblocks can have several effective roots to the dentry tree
  19  * - directory type roots are spliced into the tree when a path from one root reaches the root
  20  *   of another (see nfs_lookup())
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25
  26 #include <linux/time.h>
  27 #include <linux/kernel.h>
  28 #include <linux/mm.h>
  29 #include <linux/string.h>
  30 #include <linux/stat.h>
  31 #include <linux/errno.h>
  32 #include <linux/unistd.h>
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/sunrpc/addr.h>
  35 #include <linux/sunrpc/stats.h>
  36 #include <linux/sunrpc/metrics.h>
  37 #include <linux/sunrpc/xprtsock.h>
  38 #include <linux/sunrpc/xprtrdma.h>
  39 #include <linux/nfs_fs.h>
  40 #include <linux/nfs_mount.h>
  41 #include <linux/nfs4_mount.h>
  42 #include <linux/lockd/bind.h>
  43 #include <linux/seq_file.h>
  44 #include <linux/mount.h>
  45 #include <linux/namei.h>
  46 #include <linux/nfs_idmap.h>
  47 #include <linux/vfs.h>
  48 #include <linux/inet.h>
  49 #include <linux/in6.h>
  50 #include <linux/slab.h>
  51 #include <net/ipv6.h>
  52 #include <linux/netdevice.h>
  53 #include <linux/nfs_xdr.h>
  54 #include <linux/magic.h>
  55 #include <linux/parser.h>
  56 #include <linux/nsproxy.h>
  57 #include <linux/rcupdate.h>
  58
  59 #include <asm/uaccess.h>
  60
  61 #include "nfs4_fs.h"
  62 #include "callback.h"
  63 #include "delegation.h"
  64 #include "iostat.h"
  65 #include "internal.h"
  66 #include "fscache.h"
  67 #include "nfs4session.h"
  68 #include "pnfs.h"
  69 #include "nfs.h"
  70
  71 #define NFSDBG_FACILITY         NFSDBG_VFS
  72 #define NFS_TEXT_DATA           1
  73
  74 #if IS_ENABLED(CONFIG_NFS_V3)
  75 #define NFS_DEFAULT_VERSION 3
  76 #else
  77 #define NFS_DEFAULT_VERSION 2
  78 #endif
  79
  80 enum {
  81         /* Mount options that take no arguments */
  82         Opt_soft, Opt_hard,
  83         Opt_posix, Opt_noposix,
  84         Opt_cto, Opt_nocto,
  85         Opt_ac, Opt_noac,
  86         Opt_lock, Opt_nolock,
  87         Opt_udp, Opt_tcp, Opt_rdma,
  88         Opt_acl, Opt_noacl,
  89         Opt_rdirplus, Opt_nordirplus,
  90         Opt_sharecache, Opt_nosharecache,
  91         Opt_resvport, Opt_noresvport,
  92         Opt_fscache, Opt_nofscache,
  93         Opt_migration, Opt_nomigration,
  94
  95         /* Mount options that take integer arguments */
  96         Opt_port,
  97         Opt_rsize, Opt_wsize, Opt_bsize,
  98         Opt_timeo, Opt_retrans,
  99         Opt_acregmin, Opt_acregmax,
 100         Opt_acdirmin, Opt_acdirmax,
 101         Opt_actimeo,
 102         Opt_namelen,
 103         Opt_mountport,
 104         Opt_mountvers,
 105         Opt_minorversion,
 106
 107         /* Mount options that take string arguments */
 108         Opt_nfsvers,
 109         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
 110         Opt_addr, Opt_mountaddr, Opt_clientaddr,
 111         Opt_lookupcache,
 112         Opt_fscache_uniq,
 113         Opt_local_lock,
 114
 115         /* Special mount options */
 116         Opt_userspace, Opt_deprecated, Opt_sloppy,
 117
 118         Opt_err
 119 };
 120
 121 static const match_table_t nfs_mount_option_tokens = {
 122         { Opt_userspace, "bg" },
 123         { Opt_userspace, "fg" },
 124         { Opt_userspace, "retry=%s" },
 125
 126         { Opt_sloppy, "sloppy" },
 127
 128         { Opt_soft, "soft" },
 129         { Opt_hard, "hard" },
 130         { Opt_deprecated, "intr" },
 131         { Opt_deprecated, "nointr" },
 132         { Opt_posix, "posix" },
 133         { Opt_noposix, "noposix" },
 134         { Opt_cto, "cto" },
 135         { Opt_nocto, "nocto" },
 136         { Opt_ac, "ac" },
 137         { Opt_noac, "noac" },
 138         { Opt_lock, "lock" },
 139         { Opt_nolock, "nolock" },
 140         { Opt_udp, "udp" },
 141         { Opt_tcp, "tcp" },
 142         { Opt_rdma, "rdma" },
 143         { Opt_acl, "acl" },
 144         { Opt_noacl, "noacl" },
 145         { Opt_rdirplus, "rdirplus" },
 146         { Opt_nordirplus, "nordirplus" },
 147         { Opt_sharecache, "sharecache" },
 148         { Opt_nosharecache, "nosharecache" },
 149         { Opt_resvport, "resvport" },
 150         { Opt_noresvport, "noresvport" },
 151         { Opt_fscache, "fsc" },
 152         { Opt_nofscache, "nofsc" },
 153         { Opt_migration, "migration" },
 154         { Opt_nomigration, "nomigration" },
 155
 156         { Opt_port, "port=%s" },
 157         { Opt_rsize, "rsize=%s" },
 158         { Opt_wsize, "wsize=%s" },
 159         { Opt_bsize, "bsize=%s" },
 160         { Opt_timeo, "timeo=%s" },
 161         { Opt_retrans, "retrans=%s" },
 162         { Opt_acregmin, "acregmin=%s" },
 163         { Opt_acregmax, "acregmax=%s" },
 164         { Opt_acdirmin, "acdirmin=%s" },
 165         { Opt_acdirmax, "acdirmax=%s" },
 166         { Opt_actimeo, "actimeo=%s" },
 167         { Opt_namelen, "namlen=%s" },
 168         { Opt_mountport, "mountport=%s" },
 169         { Opt_mountvers, "mountvers=%s" },
 170         { Opt_minorversion, "minorversion=%s" },
 171
 172         { Opt_nfsvers, "nfsvers=%s" },
 173         { Opt_nfsvers, "vers=%s" },
 174
 175         { Opt_sec, "sec=%s" },
 176         { Opt_proto, "proto=%s" },
 177         { Opt_mountproto, "mountproto=%s" },
 178         { Opt_addr, "addr=%s" },
 179         { Opt_clientaddr, "clientaddr=%s" },
 180         { Opt_mounthost, "mounthost=%s" },
 181         { Opt_mountaddr, "mountaddr=%s" },
 182
 183         { Opt_lookupcache, "lookupcache=%s" },
 184         { Opt_fscache_uniq, "fsc=%s" },
 185         { Opt_local_lock, "local_lock=%s" },
 186
 187         /* The following needs to be listed after all other options */
 188         { Opt_nfsvers, "v%s" },
 189
 190         { Opt_err, NULL }
 191 };
 192
 193 enum {
 194         Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
 195
 196         Opt_xprt_err
 197 };
 198
 199 static const match_table_t nfs_xprt_protocol_tokens = {
 200         { Opt_xprt_udp, "udp" },
 201         { Opt_xprt_udp6, "udp6" },
 202         { Opt_xprt_tcp, "tcp" },
 203         { Opt_xprt_tcp6, "tcp6" },
 204         { Opt_xprt_rdma, "rdma" },
 205
 206         { Opt_xprt_err, NULL }
 207 };
 208
 209 enum {
 210         Opt_sec_none, Opt_sec_sys,
 211         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 212         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 213         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 214
 215         Opt_sec_err
 216 };
 217
 218 static const match_table_t nfs_secflavor_tokens = {
 219         { Opt_sec_none, "none" },
 220         { Opt_sec_none, "null" },
 221         { Opt_sec_sys, "sys" },
 222
 223         { Opt_sec_krb5, "krb5" },
 224         { Opt_sec_krb5i, "krb5i" },
 225         { Opt_sec_krb5p, "krb5p" },
 226
 227         { Opt_sec_lkey, "lkey" },
 228         { Opt_sec_lkeyi, "lkeyi" },
 229         { Opt_sec_lkeyp, "lkeyp" },
 230
 231         { Opt_sec_spkm, "spkm3" },
 232         { Opt_sec_spkmi, "spkm3i" },
 233         { Opt_sec_spkmp, "spkm3p" },
 234
 235         { Opt_sec_err, NULL }
 236 };
 237
 238 enum {
 239         Opt_lookupcache_all, Opt_lookupcache_positive,
 240         Opt_lookupcache_none,
 241
 242         Opt_lookupcache_err
 243 };
 244
 245 static match_table_t nfs_lookupcache_tokens = {
 246         { Opt_lookupcache_all, "all" },
 247         { Opt_lookupcache_positive, "pos" },
 248         { Opt_lookupcache_positive, "positive" },
 249         { Opt_lookupcache_none, "none" },
 250
 251         { Opt_lookupcache_err, NULL }
 252 };
 253
 254 enum {
 255         Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
 256         Opt_local_lock_none,
 257
 258         Opt_local_lock_err
 259 };
 260
 261 static match_table_t nfs_local_lock_tokens = {
 262         { Opt_local_lock_all, "all" },
 263         { Opt_local_lock_flock, "flock" },
 264         { Opt_local_lock_posix, "posix" },
 265         { Opt_local_lock_none, "none" },
 266
 267         { Opt_local_lock_err, NULL }
 268 };
 269
 270 enum {
 271         Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
 272         Opt_vers_4_1, Opt_vers_4_2,
 273
 274         Opt_vers_err
 275 };
 276
 277 static match_table_t nfs_vers_tokens = {
 278         { Opt_vers_2, "2" },
 279         { Opt_vers_3, "3" },
 280         { Opt_vers_4, "4" },
 281         { Opt_vers_4_0, "4.0" },
 282         { Opt_vers_4_1, "4.1" },
 283         { Opt_vers_4_2, "4.2" },
 284
 285         { Opt_vers_err, NULL }
 286 };
 287
 288 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
 289                 int flags, const char *dev_name, void *raw_data);
 290
 291 struct file_system_type nfs_fs_type = {
 292         .owner          = THIS_MODULE,
 293         .name           = "nfs",
 294         .mount          = nfs_fs_mount,
 295         .kill_sb        = nfs_kill_super,
 296         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 297 };
 298 MODULE_ALIAS_FS("nfs");
 299 EXPORT_SYMBOL_GPL(nfs_fs_type);
 300
 301 struct file_system_type nfs_xdev_fs_type = {
 302         .owner          = THIS_MODULE,
 303         .name           = "nfs",
 304         .mount          = nfs_xdev_mount,
 305         .kill_sb        = nfs_kill_super,
 306         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 307 };
 308
 309 const struct super_operations nfs_sops = {
 310         .alloc_inode    = nfs_alloc_inode,
 311         .destroy_inode  = nfs_destroy_inode,
 312         .write_inode    = nfs_write_inode,
 313         .drop_inode     = nfs_drop_inode,
 314         .put_super      = nfs_put_super,
 315         .statfs         = nfs_statfs,
 316         .evict_inode    = nfs_evict_inode,
 317         .umount_begin   = nfs_umount_begin,
 318         .show_options   = nfs_show_options,
 319         .show_devname   = nfs_show_devname,
 320         .show_path      = nfs_show_path,
 321         .show_stats     = nfs_show_stats,
 322         .remount_fs     = nfs_remount,
 323 };
 324 EXPORT_SYMBOL_GPL(nfs_sops);
 325
 326 #if IS_ENABLED(CONFIG_NFS_V4)
 327 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
 328 static int nfs4_validate_mount_data(void *options,
 329         struct nfs_parsed_mount_data *args, const char *dev_name);
 330
 331 struct file_system_type nfs4_fs_type = {
 332         .owner          = THIS_MODULE,
 333         .name           = "nfs4",
 334         .mount          = nfs_fs_mount,
 335         .kill_sb        = nfs_kill_super,
 336         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 337 };
 338 MODULE_ALIAS_FS("nfs4");
 339 MODULE_ALIAS("nfs4");
 340 EXPORT_SYMBOL_GPL(nfs4_fs_type);
 341
 342 static int __init register_nfs4_fs(void)
 343 {
 344         return register_filesystem(&nfs4_fs_type);
 345 }
 346
 347 static void unregister_nfs4_fs(void)
 348 {
 349         unregister_filesystem(&nfs4_fs_type);
 350 }
 351 #else
 352 static int __init register_nfs4_fs(void)
 353 {
 354         return 0;
 355 }
 356
 357 static void unregister_nfs4_fs(void)
 358 {
 359 }
 360 #endif
 361
 362 static struct shrinker acl_shrinker = {
 363         .shrink         = nfs_access_cache_shrinker,
 364         .seeks          = DEFAULT_SEEKS,
 365 };
 366
 367 /*
 368  * Register the NFS filesystems
 369  */
 370 int __init register_nfs_fs(void)
 371 {
 372         int ret;
 373
 374         ret = register_filesystem(&nfs_fs_type);
 375         if (ret < 0)
 376                 goto error_0;
 377
 378         ret = register_nfs4_fs();
 379         if (ret < 0)
 380                 goto error_1;
 381
 382         ret = nfs_register_sysctl();
 383         if (ret < 0)
 384                 goto error_2;
 385         register_shrinker(&acl_shrinker);
 386         return 0;
 387
 388 error_2:
 389         unregister_nfs4_fs();
 390 error_1:
 391         unregister_filesystem(&nfs_fs_type);
 392 error_0:
 393         return ret;
 394 }
 395
 396 /*
 397  * Unregister the NFS filesystems
 398  */
 399 void __exit unregister_nfs_fs(void)
 400 {
 401         unregister_shrinker(&acl_shrinker);
 402         nfs_unregister_sysctl();
 403         unregister_nfs4_fs();
 404         unregister_filesystem(&nfs_fs_type);
 405 }
 406
 407 void nfs_sb_active(struct super_block *sb)
 408 {
 409         struct nfs_server *server = NFS_SB(sb);
 410
 411         if (atomic_inc_return(&server->active) == 1)
 412                 atomic_inc(&sb->s_active);
 413 }
 414 EXPORT_SYMBOL_GPL(nfs_sb_active);
 415
 416 void nfs_sb_deactive(struct super_block *sb)
 417 {
 418         struct nfs_server *server = NFS_SB(sb);
 419
 420         if (atomic_dec_and_test(&server->active))
 421                 deactivate_super(sb);
 422 }
 423 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
 424
 425 /*
 426  * Deliver file system statistics to userspace
 427  */
 428 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 429 {
 430         struct nfs_server *server = NFS_SB(dentry->d_sb);
 431         unsigned char blockbits;
 432         unsigned long blockres;
 433         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 434         struct nfs_fsstat res;
 435         int error = -ENOMEM;
 436
 437         res.fattr = nfs_alloc_fattr();
 438         if (res.fattr == NULL)
 439                 goto out_err;
 440
 441         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 442         if (unlikely(error == -ESTALE)) {
 443                 struct dentry *pd_dentry;
 444
 445                 pd_dentry = dget_parent(dentry);
 446                 if (pd_dentry != NULL) {
 447                         nfs_zap_caches(pd_dentry->d_inode);
 448                         dput(pd_dentry);
 449                 }
 450         }
 451         nfs_free_fattr(res.fattr);
 452         if (error < 0)
 453                 goto out_err;
 454
 455         buf->f_type = NFS_SUPER_MAGIC;
 456
 457         /*
 458          * Current versions of glibc do not correctly handle the
 459          * case where f_frsize != f_bsize.  Eventually we want to
 460          * report the value of wtmult in this field.
 461          */
 462         buf->f_frsize = dentry->d_sb->s_blocksize;
 463
 464         /*
 465          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 466          * are reported in units of f_frsize.  Linux hasn't had
 467          * an f_frsize field in its statfs struct until recently,
 468          * thus historically Linux's sys_statfs reports these
 469          * fields in units of f_bsize.
 470          */
 471         buf->f_bsize = dentry->d_sb->s_blocksize;
 472         blockbits = dentry->d_sb->s_blocksize_bits;
 473         blockres = (1 << blockbits) - 1;
 474         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 475         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 476         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 477
 478         buf->f_files = res.tfiles;
 479         buf->f_ffree = res.afiles;
 480
 481         buf->f_namelen = server->namelen;
 482
 483         return 0;
 484
 485  out_err:
 486         dprintk("%s: statfs error = %d\n", __func__, -error);
 487         return error;
 488 }
 489 EXPORT_SYMBOL_GPL(nfs_statfs);
 490
 491 /*
 492  * Map the security flavour number to a name
 493  */
 494 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 495 {
 496         static const struct {
 497                 rpc_authflavor_t flavour;
 498                 const char *str;
 499         } sec_flavours[] = {
 500                 { RPC_AUTH_NULL, "null" },
 501                 { RPC_AUTH_UNIX, "sys" },
 502                 { RPC_AUTH_GSS_KRB5, "krb5" },
 503                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 504                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 505                 { RPC_AUTH_GSS_LKEY, "lkey" },
 506                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 507                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 508                 { RPC_AUTH_GSS_SPKM, "spkm" },
 509                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 510                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 511                 { UINT_MAX, "unknown" }
 512         };
 513         int i;
 514
 515         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 516                 if (sec_flavours[i].flavour == flavour)
 517                         break;
 518         }
 519         return sec_flavours[i].str;
 520 }
 521
 522 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
 523                                   int showdefaults)
 524 {
 525         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
 526
 527         seq_printf(m, ",mountproto=");
 528         switch (sap->sa_family) {
 529         case AF_INET:
 530                 switch (nfss->mountd_protocol) {
 531                 case IPPROTO_UDP:
 532                         seq_printf(m, RPCBIND_NETID_UDP);
 533                         break;
 534                 case IPPROTO_TCP:
 535                         seq_printf(m, RPCBIND_NETID_TCP);
 536                         break;
 537                 default:
 538                         if (showdefaults)
 539                                 seq_printf(m, "auto");
 540                 }
 541                 break;
 542         case AF_INET6:
 543                 switch (nfss->mountd_protocol) {
 544                 case IPPROTO_UDP:
 545                         seq_printf(m, RPCBIND_NETID_UDP6);
 546                         break;
 547                 case IPPROTO_TCP:
 548                         seq_printf(m, RPCBIND_NETID_TCP6);
 549                         break;
 550                 default:
 551                         if (showdefaults)
 552                                 seq_printf(m, "auto");
 553                 }
 554                 break;
 555         default:
 556                 if (showdefaults)
 557                         seq_printf(m, "auto");
 558         }
 559 }
 560
 561 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 562                                     int showdefaults)
 563 {
 564         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 565
 566         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
 567                 return;
 568
 569         switch (sap->sa_family) {
 570         case AF_INET: {
 571                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 572                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 573                 break;
 574         }
 575         case AF_INET6: {
 576                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 577                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 578                 break;
 579         }
 580         default:
 581                 if (showdefaults)
 582                         seq_printf(m, ",mountaddr=unspecified");
 583         }
 584
 585         if (nfss->mountd_version || showdefaults)
 586                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 587         if ((nfss->mountd_port &&
 588                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
 589                 showdefaults)
 590                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 591
 592         nfs_show_mountd_netid(m, nfss, showdefaults);
 593 }
 594
 595 #if IS_ENABLED(CONFIG_NFS_V4)
 596 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 597                                     int showdefaults)
 598 {
 599         struct nfs_client *clp = nfss->nfs_client;
 600
 601         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 602 }
 603 #else
 604 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 605                                     int showdefaults)
 606 {
 607 }
 608 #endif
 609
 610 static void nfs_show_nfs_version(struct seq_file *m,
 611                 unsigned int version,
 612                 unsigned int minorversion)
 613 {
 614         seq_printf(m, ",vers=%u", version);
 615         if (version == 4)
 616                 seq_printf(m, ".%u", minorversion);
 617 }
 618
 619 /*
 620  * Describe the mount options in force on this server representation
 621  */
 622 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 623                                    int showdefaults)
 624 {
 625         static const struct proc_nfs_info {
 626                 int flag;
 627                 const char *str;
 628                 const char *nostr;
 629         } nfs_info[] = {
 630                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 631                 { NFS_MOUNT_POSIX, ",posix", "" },
 632                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 633                 { NFS_MOUNT_NOAC, ",noac", "" },
 634                 { NFS_MOUNT_NONLM, ",nolock", "" },
 635                 { NFS_MOUNT_NOACL, ",noacl", "" },
 636                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 637                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 638                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 639                 { 0, NULL, NULL }
 640         };
 641         const struct proc_nfs_info *nfs_infop;
 642         struct nfs_client *clp = nfss->nfs_client;
 643         u32 version = clp->rpc_ops->version;
 644         int local_flock, local_fcntl;
 645
 646         nfs_show_nfs_version(m, version, clp->cl_minorversion);
 647         seq_printf(m, ",rsize=%u", nfss->rsize);
 648         seq_printf(m, ",wsize=%u", nfss->wsize);
 649         if (nfss->bsize != 0)
 650                 seq_printf(m, ",bsize=%u", nfss->bsize);
 651         seq_printf(m, ",namlen=%u", nfss->namelen);
 652         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 653                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 654         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 655                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 656         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 657                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 658         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 659                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 660         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 661                 if (nfss->flags & nfs_infop->flag)
 662                         seq_puts(m, nfs_infop->str);
 663                 else
 664                         seq_puts(m, nfs_infop->nostr);
 665         }
 666         rcu_read_lock();
 667         seq_printf(m, ",proto=%s",
 668                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 669         rcu_read_unlock();
 670         if (version == 4) {
 671                 if (nfss->port != NFS_PORT)
 672                         seq_printf(m, ",port=%u", nfss->port);
 673         } else
 674                 if (nfss->port)
 675                         seq_printf(m, ",port=%u", nfss->port);
 676
 677         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 678         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 679         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 680
 681         if (version != 4)
 682                 nfs_show_mountd_options(m, nfss, showdefaults);
 683         else
 684                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 685
 686         if (nfss->options & NFS_OPTION_FSCACHE)
 687                 seq_printf(m, ",fsc");
 688
 689         if (nfss->options & NFS_OPTION_MIGRATION)
 690                 seq_printf(m, ",migration");
 691
 692         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
 693                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 694                         seq_printf(m, ",lookupcache=none");
 695                 else
 696                         seq_printf(m, ",lookupcache=pos");
 697         }
 698
 699         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
 700         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
 701
 702         if (!local_flock && !local_fcntl)
 703                 seq_printf(m, ",local_lock=none");
 704         else if (local_flock && local_fcntl)
 705                 seq_printf(m, ",local_lock=all");
 706         else if (local_flock)
 707                 seq_printf(m, ",local_lock=flock");
 708         else
 709                 seq_printf(m, ",local_lock=posix");
 710 }
 711
 712 /*
 713  * Describe the mount options on this VFS mountpoint
 714  */
 715 int nfs_show_options(struct seq_file *m, struct dentry *root)
 716 {
 717         struct nfs_server *nfss = NFS_SB(root->d_sb);
 718
 719         nfs_show_mount_options(m, nfss, 0);
 720
 721         rcu_read_lock();
 722         seq_printf(m, ",addr=%s",
 723                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 724                                                         RPC_DISPLAY_ADDR));
 725         rcu_read_unlock();
 726
 727         return 0;
 728 }
 729 EXPORT_SYMBOL_GPL(nfs_show_options);
 730
 731 #if IS_ENABLED(CONFIG_NFS_V4)
 732 #ifdef CONFIG_NFS_V4_1
 733 static void show_sessions(struct seq_file *m, struct nfs_server *server)
 734 {
 735         if (nfs4_has_session(server->nfs_client))
 736                 seq_printf(m, ",sessions");
 737 }
 738 #else
 739 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
 740 #endif
 741 #endif
 742
 743 #ifdef CONFIG_NFS_V4_1
 744 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 745 {
 746         seq_printf(m, ",pnfs=");
 747         if (server->pnfs_curr_ld)
 748                 seq_printf(m, "%s", server->pnfs_curr_ld->name);
 749         else
 750                 seq_printf(m, "not configured");
 751 }
 752
 753 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 754 {
 755         if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
 756                 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
 757                 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
 758                            "date='%llu,%u'",
 759                            impl_id->name, impl_id->domain,
 760                            impl_id->date.seconds, impl_id->date.nseconds);
 761         }
 762 }
 763 #else
 764 #if IS_ENABLED(CONFIG_NFS_V4)
 765 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 766 {
 767 }
 768 #endif
 769 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 770 {
 771 }
 772 #endif
 773
 774 int nfs_show_devname(struct seq_file *m, struct dentry *root)
 775 {
 776         char *page = (char *) __get_free_page(GFP_KERNEL);
 777         char *devname, *dummy;
 778         int err = 0;
 779         if (!page)
 780                 return -ENOMEM;
 781         devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
 782         if (IS_ERR(devname))
 783                 err = PTR_ERR(devname);
 784         else
 785                 seq_escape(m, devname, " \t\n\\");
 786         free_page((unsigned long)page);
 787         return err;
 788 }
 789 EXPORT_SYMBOL_GPL(nfs_show_devname);
 790
 791 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
 792 {
 793         seq_puts(m, "/");
 794         return 0;
 795 }
 796 EXPORT_SYMBOL_GPL(nfs_show_path);
 797
 798 /*
 799  * Present statistical information for this VFS mountpoint
 800  */
 801 int nfs_show_stats(struct seq_file *m, struct dentry *root)
 802 {
 803         int i, cpu;
 804         struct nfs_server *nfss = NFS_SB(root->d_sb);
 805         struct rpc_auth *auth = nfss->client->cl_auth;
 806         struct nfs_iostats totals = { };
 807
 808         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 809
 810         /*
 811          * Display all mount option settings
 812          */
 813         seq_printf(m, "\n\topts:\t");
 814         seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 815         seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 816         seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 817         seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 818         nfs_show_mount_options(m, nfss, 1);
 819
 820         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 821
 822         show_implementation_id(m, nfss);
 823
 824         seq_printf(m, "\n\tcaps:\t");
 825         seq_printf(m, "caps=0x%x", nfss->caps);
 826         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 827         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 828         seq_printf(m, ",bsize=%u", nfss->bsize);
 829         seq_printf(m, ",namlen=%u", nfss->namelen);
 830
 831 #if IS_ENABLED(CONFIG_NFS_V4)
 832         if (nfss->nfs_client->rpc_ops->version == 4) {
 833                 seq_printf(m, "\n\tnfsv4:\t");
 834                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 835                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 836                 seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
 837                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 838                 show_sessions(m, nfss);
 839                 show_pnfs(m, nfss);
 840         }
 841 #endif
 842
 843         /*
 844          * Display security flavor in effect for this mount
 845          */
 846         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 847         if (auth->au_flavor)
 848                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 849
 850         /*
 851          * Display superblock I/O counters
 852          */
 853         for_each_possible_cpu(cpu) {
 854                 struct nfs_iostats *stats;
 855
 856                 preempt_disable();
 857                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 858
 859                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 860                         totals.events[i] += stats->events[i];
 861                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 862                         totals.bytes[i] += stats->bytes[i];
 863 #ifdef CONFIG_NFS_FSCACHE
 864                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 865                         totals.fscache[i] += stats->fscache[i];
 866 #endif
 867
 868                 preempt_enable();
 869         }
 870
 871         seq_printf(m, "\n\tevents:\t");
 872         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 873                 seq_printf(m, "%lu ", totals.events[i]);
 874         seq_printf(m, "\n\tbytes:\t");
 875         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 876                 seq_printf(m, "%Lu ", totals.bytes[i]);
 877 #ifdef CONFIG_NFS_FSCACHE
 878         if (nfss->options & NFS_OPTION_FSCACHE) {
 879                 seq_printf(m, "\n\tfsc:\t");
 880                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 881                         seq_printf(m, "%Lu ", totals.bytes[i]);
 882         }
 883 #endif
 884         seq_printf(m, "\n");
 885
 886         rpc_print_iostats(m, nfss->client);
 887
 888         return 0;
 889 }
 890 EXPORT_SYMBOL_GPL(nfs_show_stats);
 891
 892 /*
 893  * Begin unmount by attempting to remove all automounted mountpoints we added
 894  * in response to xdev traversals and referrals
 895  */
 896 void nfs_umount_begin(struct super_block *sb)
 897 {
 898         struct nfs_server *server;
 899         struct rpc_clnt *rpc;
 900
 901         server = NFS_SB(sb);
 902         /* -EIO all pending I/O */
 903         rpc = server->client_acl;
 904         if (!IS_ERR(rpc))
 905                 rpc_killall_tasks(rpc);
 906         rpc = server->client;
 907         if (!IS_ERR(rpc))
 908                 rpc_killall_tasks(rpc);
 909 }
 910 EXPORT_SYMBOL_GPL(nfs_umount_begin);
 911
 912 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
 913 {
 914         struct nfs_parsed_mount_data *data;
 915
 916         data = kzalloc(sizeof(*data), GFP_KERNEL);
 917         if (data) {
 918                 data->acregmin          = NFS_DEF_ACREGMIN;
 919                 data->acregmax          = NFS_DEF_ACREGMAX;
 920                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 921                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 922                 data->mount_server.port = NFS_UNSPEC_PORT;
 923                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 924                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 925                 data->auth_flavors[0]   = RPC_AUTH_MAXFLAVOR;
 926                 data->auth_flavor_len   = 1;
 927                 data->minorversion      = 0;
 928                 data->need_mount        = true;
 929                 data->net               = current->nsproxy->net_ns;
 930                 security_init_mnt_opts(&data->lsm_opts);
 931         }
 932         return data;
 933 }
 934
 935 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
 936 {
 937         if (data) {
 938                 kfree(data->client_address);
 939                 kfree(data->mount_server.hostname);
 940                 kfree(data->nfs_server.export_path);
 941                 kfree(data->nfs_server.hostname);
 942                 kfree(data->fscache_uniq);
 943                 security_free_mnt_opts(&data->lsm_opts);
 944                 kfree(data);
 945         }
 946 }
 947
 948 /*
 949  * Sanity-check a server address provided by the mount command.
 950  *
 951  * Address family must be initialized, and address must not be
 952  * the ANY address for that family.
 953  */
 954 static int nfs_verify_server_address(struct sockaddr *addr)
 955 {
 956         switch (addr->sa_family) {
 957         case AF_INET: {
 958                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 959                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 960         }
 961         case AF_INET6: {
 962                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 963                 return !ipv6_addr_any(sa);
 964         }
 965         }
 966
 967         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 968         return 0;
 969 }
 970
 971 /*
 972  * Select between a default port value and a user-specified port value.
 973  * If a zero value is set, then autobind will be used.
 974  */
 975 static void nfs_set_port(struct sockaddr *sap, int *port,
 976                                  const unsigned short default_port)
 977 {
 978         if (*port == NFS_UNSPEC_PORT)
 979                 *port = default_port;
 980
 981         rpc_set_port(sap, *port);
 982 }
 983
 984 /*
 985  * Sanity check the NFS transport protocol.
 986  *
 987  */
 988 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 989 {
 990         switch (mnt->nfs_server.protocol) {
 991         case XPRT_TRANSPORT_UDP:
 992         case XPRT_TRANSPORT_TCP:
 993         case XPRT_TRANSPORT_RDMA:
 994                 break;
 995         default:
 996                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 997         }
 998 }
 999
1000 /*
1001  * For text based NFSv2/v3 mounts, the mount protocol transport default
1002  * settings should depend upon the specified NFS transport.
1003  */
1004 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1005 {
1006         nfs_validate_transport_protocol(mnt);
1007
1008         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1009             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1010                         return;
1011         switch (mnt->nfs_server.protocol) {
1012         case XPRT_TRANSPORT_UDP:
1013                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1014                 break;
1015         case XPRT_TRANSPORT_TCP:
1016         case XPRT_TRANSPORT_RDMA:
1017                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1018         }
1019 }
1020
1021 /*
1022  * Parse the value of the 'sec=' option.
1023  */
1024 static int nfs_parse_security_flavors(char *value,
1025                                       struct nfs_parsed_mount_data *mnt)
1026 {
1027         substring_t args[MAX_OPT_ARGS];
1028
1029         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1030
1031         switch (match_token(value, nfs_secflavor_tokens, args)) {
1032         case Opt_sec_none:
1033                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
1034                 break;
1035         case Opt_sec_sys:
1036                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1037                 break;
1038         case Opt_sec_krb5:
1039                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1040                 break;
1041         case Opt_sec_krb5i:
1042                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1043                 break;
1044         case Opt_sec_krb5p:
1045                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1046                 break;
1047         case Opt_sec_lkey:
1048                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1049                 break;
1050         case Opt_sec_lkeyi:
1051                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1052                 break;
1053         case Opt_sec_lkeyp:
1054                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1055                 break;
1056         case Opt_sec_spkm:
1057                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1058                 break;
1059         case Opt_sec_spkmi:
1060                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1061                 break;
1062         case Opt_sec_spkmp:
1063                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1064                 break;
1065         default:
1066                 return 0;
1067         }
1068
1069         mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1070         mnt->auth_flavor_len = 1;
1071         return 1;
1072 }
1073
1074 static int nfs_parse_version_string(char *string,
1075                 struct nfs_parsed_mount_data *mnt,
1076                 substring_t *args)
1077 {
1078         mnt->flags &= ~NFS_MOUNT_VER3;
1079         switch (match_token(string, nfs_vers_tokens, args)) {
1080         case Opt_vers_2:
1081                 mnt->version = 2;
1082                 break;
1083         case Opt_vers_3:
1084                 mnt->flags |= NFS_MOUNT_VER3;
1085                 mnt->version = 3;
1086                 break;
1087         case Opt_vers_4:
1088                 /* Backward compatibility option. In future,
1089                  * the mount program should always supply
1090                  * a NFSv4 minor version number.
1091                  */
1092                 mnt->version = 4;
1093                 break;
1094         case Opt_vers_4_0:
1095                 mnt->version = 4;
1096                 mnt->minorversion = 0;
1097                 break;
1098         case Opt_vers_4_1:
1099                 mnt->version = 4;
1100                 mnt->minorversion = 1;
1101                 break;
1102         case Opt_vers_4_2:
1103                 mnt->version = 4;
1104                 mnt->minorversion = 2;
1105                 break;
1106         default:
1107                 return 0;
1108         }
1109         return 1;
1110 }
1111
1112 static int nfs_get_option_str(substring_t args[], char **option)
1113 {
1114         kfree(*option);
1115         *option = match_strdup(args);
1116         return !*option;
1117 }
1118
1119 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1120 {
1121         int rc;
1122         char *string;
1123
1124         string = match_strdup(args);
1125         if (string == NULL)
1126                 return -ENOMEM;
1127         rc = kstrtoul(string, 10, option);
1128         kfree(string);
1129
1130         return rc;
1131 }
1132
1133 /*
1134  * Error-check and convert a string of mount options from user space into
1135  * a data structure.  The whole mount string is processed; bad options are
1136  * skipped as they are encountered.  If there were no errors, return 1;
1137  * otherwise return 0 (zero).
1138  */
1139 static int nfs_parse_mount_options(char *raw,
1140                                    struct nfs_parsed_mount_data *mnt)
1141 {
1142         char *p, *string, *secdata;
1143         int rc, sloppy = 0, invalid_option = 0;
1144         unsigned short protofamily = AF_UNSPEC;
1145         unsigned short mountfamily = AF_UNSPEC;
1146
1147         if (!raw) {
1148                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1149                 return 1;
1150         }
1151         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1152
1153         secdata = alloc_secdata();
1154         if (!secdata)
1155                 goto out_nomem;
1156
1157         rc = security_sb_copy_data(raw, secdata);
1158         if (rc)
1159                 goto out_security_failure;
1160
1161         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1162         if (rc)
1163                 goto out_security_failure;
1164
1165         free_secdata(secdata);
1166
1167         while ((p = strsep(&raw, ",")) != NULL) {
1168                 substring_t args[MAX_OPT_ARGS];
1169                 unsigned long option;
1170                 int token;
1171
1172                 if (!*p)
1173                         continue;
1174
1175                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1176
1177                 token = match_token(p, nfs_mount_option_tokens, args);
1178                 switch (token) {
1179
1180                 /*
1181                  * boolean options:  foo/nofoo
1182                  */
1183                 case Opt_soft:
1184                         mnt->flags |= NFS_MOUNT_SOFT;
1185                         break;
1186                 case Opt_hard:
1187                         mnt->flags &= ~NFS_MOUNT_SOFT;
1188                         break;
1189                 case Opt_posix:
1190                         mnt->flags |= NFS_MOUNT_POSIX;
1191                         break;
1192                 case Opt_noposix:
1193                         mnt->flags &= ~NFS_MOUNT_POSIX;
1194                         break;
1195                 case Opt_cto:
1196                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1197                         break;
1198                 case Opt_nocto:
1199                         mnt->flags |= NFS_MOUNT_NOCTO;
1200                         break;
1201                 case Opt_ac:
1202                         mnt->flags &= ~NFS_MOUNT_NOAC;
1203                         break;
1204                 case Opt_noac:
1205                         mnt->flags |= NFS_MOUNT_NOAC;
1206                         break;
1207                 case Opt_lock:
1208                         mnt->flags &= ~NFS_MOUNT_NONLM;
1209                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1210                                         NFS_MOUNT_LOCAL_FCNTL);
1211                         break;
1212                 case Opt_nolock:
1213                         mnt->flags |= NFS_MOUNT_NONLM;
1214                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1215                                        NFS_MOUNT_LOCAL_FCNTL);
1216                         break;
1217                 case Opt_udp:
1218                         mnt->flags &= ~NFS_MOUNT_TCP;
1219                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1220                         break;
1221                 case Opt_tcp:
1222                         mnt->flags |= NFS_MOUNT_TCP;
1223                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1224                         break;
1225                 case Opt_rdma:
1226                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1227                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1228                         xprt_load_transport(p);
1229                         break;
1230                 case Opt_acl:
1231                         mnt->flags &= ~NFS_MOUNT_NOACL;
1232                         break;
1233                 case Opt_noacl:
1234                         mnt->flags |= NFS_MOUNT_NOACL;
1235                         break;
1236                 case Opt_rdirplus:
1237                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1238                         break;
1239                 case Opt_nordirplus:
1240                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1241                         break;
1242                 case Opt_sharecache:
1243                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1244                         break;
1245                 case Opt_nosharecache:
1246                         mnt->flags |= NFS_MOUNT_UNSHARED;
1247                         break;
1248                 case Opt_resvport:
1249                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1250                         break;
1251                 case Opt_noresvport:
1252                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1253                         break;
1254                 case Opt_fscache:
1255                         mnt->options |= NFS_OPTION_FSCACHE;
1256                         kfree(mnt->fscache_uniq);
1257                         mnt->fscache_uniq = NULL;
1258                         break;
1259                 case Opt_nofscache:
1260                         mnt->options &= ~NFS_OPTION_FSCACHE;
1261                         kfree(mnt->fscache_uniq);
1262                         mnt->fscache_uniq = NULL;
1263                         break;
1264                 case Opt_migration:
1265                         mnt->options |= NFS_OPTION_MIGRATION;
1266                         break;
1267                 case Opt_nomigration:
1268                         mnt->options &= NFS_OPTION_MIGRATION;
1269                         break;
1270
1271                 /*
1272                  * options that take numeric values
1273                  */
1274                 case Opt_port:
1275                         if (nfs_get_option_ul(args, &option) ||
1276                             option > USHRT_MAX)
1277                                 goto out_invalid_value;
1278                         mnt->nfs_server.port = option;
1279                         break;
1280                 case Opt_rsize:
1281                         if (nfs_get_option_ul(args, &option))
1282                                 goto out_invalid_value;
1283                         mnt->rsize = option;
1284                         break;
1285                 case Opt_wsize:
1286                         if (nfs_get_option_ul(args, &option))
1287                                 goto out_invalid_value;
1288                         mnt->wsize = option;
1289                         break;
1290                 case Opt_bsize:
1291                         if (nfs_get_option_ul(args, &option))
1292                                 goto out_invalid_value;
1293                         mnt->bsize = option;
1294                         break;
1295                 case Opt_timeo:
1296                         if (nfs_get_option_ul(args, &option) || option == 0)
1297                                 goto out_invalid_value;
1298                         mnt->timeo = option;
1299                         break;
1300                 case Opt_retrans:
1301                         if (nfs_get_option_ul(args, &option) || option == 0)
1302                                 goto out_invalid_value;
1303                         mnt->retrans = option;
1304                         break;
1305                 case Opt_acregmin:
1306                         if (nfs_get_option_ul(args, &option))
1307                                 goto out_invalid_value;
1308                         mnt->acregmin = option;
1309                         break;
1310                 case Opt_acregmax:
1311                         if (nfs_get_option_ul(args, &option))
1312                                 goto out_invalid_value;
1313                         mnt->acregmax = option;
1314                         break;
1315                 case Opt_acdirmin:
1316                         if (nfs_get_option_ul(args, &option))
1317                                 goto out_invalid_value;
1318                         mnt->acdirmin = option;
1319                         break;
1320                 case Opt_acdirmax:
1321                         if (nfs_get_option_ul(args, &option))
1322                                 goto out_invalid_value;
1323                         mnt->acdirmax = option;
1324                         break;
1325                 case Opt_actimeo:
1326                         if (nfs_get_option_ul(args, &option))
1327                                 goto out_invalid_value;
1328                         mnt->acregmin = mnt->acregmax =
1329                         mnt->acdirmin = mnt->acdirmax = option;
1330                         break;
1331                 case Opt_namelen:
1332                         if (nfs_get_option_ul(args, &option))
1333                                 goto out_invalid_value;
1334                         mnt->namlen = option;
1335                         break;
1336                 case Opt_mountport:
1337                         if (nfs_get_option_ul(args, &option) ||
1338                             option > USHRT_MAX)
1339                                 goto out_invalid_value;
1340                         mnt->mount_server.port = option;
1341                         break;
1342                 case Opt_mountvers:
1343                         if (nfs_get_option_ul(args, &option) ||
1344                             option < NFS_MNT_VERSION ||
1345                             option > NFS_MNT3_VERSION)
1346                                 goto out_invalid_value;
1347                         mnt->mount_server.version = option;
1348                         break;
1349                 case Opt_minorversion:
1350                         if (nfs_get_option_ul(args, &option))
1351                                 goto out_invalid_value;
1352                         if (option > NFS4_MAX_MINOR_VERSION)
1353                                 goto out_invalid_value;
1354                         mnt->minorversion = option;
1355                         break;
1356
1357                 /*
1358                  * options that take text values
1359                  */
1360                 case Opt_nfsvers:
1361                         string = match_strdup(args);
1362                         if (string == NULL)
1363                                 goto out_nomem;
1364                         rc = nfs_parse_version_string(string, mnt, args);
1365                         kfree(string);
1366                         if (!rc)
1367                                 goto out_invalid_value;
1368                         break;
1369                 case Opt_sec:
1370                         string = match_strdup(args);
1371                         if (string == NULL)
1372                                 goto out_nomem;
1373                         rc = nfs_parse_security_flavors(string, mnt);
1374                         kfree(string);
1375                         if (!rc) {
1376                                 dfprintk(MOUNT, "NFS:   unrecognized "
1377                                                 "security flavor\n");
1378                                 return 0;
1379                         }
1380                         break;
1381                 case Opt_proto:
1382                         string = match_strdup(args);
1383                         if (string == NULL)
1384                                 goto out_nomem;
1385                         token = match_token(string,
1386                                             nfs_xprt_protocol_tokens, args);
1387
1388                         protofamily = AF_INET;
1389                         switch (token) {
1390                         case Opt_xprt_udp6:
1391                                 protofamily = AF_INET6;
1392                         case Opt_xprt_udp:
1393                                 mnt->flags &= ~NFS_MOUNT_TCP;
1394                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1395                                 break;
1396                         case Opt_xprt_tcp6:
1397                                 protofamily = AF_INET6;
1398                         case Opt_xprt_tcp:
1399                                 mnt->flags |= NFS_MOUNT_TCP;
1400                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1401                                 break;
1402                         case Opt_xprt_rdma:
1403                                 /* vector side protocols to TCP */
1404                                 mnt->flags |= NFS_MOUNT_TCP;
1405                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1406                                 xprt_load_transport(string);
1407                                 break;
1408                         default:
1409                                 dfprintk(MOUNT, "NFS:   unrecognized "
1410                                                 "transport protocol\n");
1411                                 kfree(string);
1412                                 return 0;
1413                         }
1414                         kfree(string);
1415                         break;
1416                 case Opt_mountproto:
1417                         string = match_strdup(args);
1418                         if (string == NULL)
1419                                 goto out_nomem;
1420                         token = match_token(string,
1421                                             nfs_xprt_protocol_tokens, args);
1422                         kfree(string);
1423
1424                         mountfamily = AF_INET;
1425                         switch (token) {
1426                         case Opt_xprt_udp6:
1427                                 mountfamily = AF_INET6;
1428                         case Opt_xprt_udp:
1429                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1430                                 break;
1431                         case Opt_xprt_tcp6:
1432                                 mountfamily = AF_INET6;
1433                         case Opt_xprt_tcp:
1434                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1435                                 break;
1436                         case Opt_xprt_rdma: /* not used for side protocols */
1437                         default:
1438                                 dfprintk(MOUNT, "NFS:   unrecognized "
1439                                                 "transport protocol\n");
1440                                 return 0;
1441                         }
1442                         break;
1443                 case Opt_addr:
1444                         string = match_strdup(args);
1445                         if (string == NULL)
1446                                 goto out_nomem;
1447                         mnt->nfs_server.addrlen =
1448                                 rpc_pton(mnt->net, string, strlen(string),
1449                                         (struct sockaddr *)
1450                                         &mnt->nfs_server.address,
1451                                         sizeof(mnt->nfs_server.address));
1452                         kfree(string);
1453                         if (mnt->nfs_server.addrlen == 0)
1454                                 goto out_invalid_address;
1455                         break;
1456                 case Opt_clientaddr:
1457                         if (nfs_get_option_str(args, &mnt->client_address))
1458                                 goto out_nomem;
1459                         break;
1460                 case Opt_mounthost:
1461                         if (nfs_get_option_str(args,
1462                                                &mnt->mount_server.hostname))
1463                                 goto out_nomem;
1464                         break;
1465                 case Opt_mountaddr:
1466                         string = match_strdup(args);
1467                         if (string == NULL)
1468                                 goto out_nomem;
1469                         mnt->mount_server.addrlen =
1470                                 rpc_pton(mnt->net, string, strlen(string),
1471                                         (struct sockaddr *)
1472                                         &mnt->mount_server.address,
1473                                         sizeof(mnt->mount_server.address));
1474                         kfree(string);
1475                         if (mnt->mount_server.addrlen == 0)
1476                                 goto out_invalid_address;
1477                         break;
1478                 case Opt_lookupcache:
1479                         string = match_strdup(args);
1480                         if (string == NULL)
1481                                 goto out_nomem;
1482                         token = match_token(string,
1483                                         nfs_lookupcache_tokens, args);
1484                         kfree(string);
1485                         switch (token) {
1486                                 case Opt_lookupcache_all:
1487                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1488                                         break;
1489                                 case Opt_lookupcache_positive:
1490                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1491                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1492                                         break;
1493                                 case Opt_lookupcache_none:
1494                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1495                                         break;
1496                                 default:
1497                                         dfprintk(MOUNT, "NFS:   invalid "
1498                                                         "lookupcache argument\n");
1499                                         return 0;
1500                         };
1501                         break;
1502                 case Opt_fscache_uniq:
1503                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1504                                 goto out_nomem;
1505                         mnt->options |= NFS_OPTION_FSCACHE;
1506                         break;
1507                 case Opt_local_lock:
1508                         string = match_strdup(args);
1509                         if (string == NULL)
1510                                 goto out_nomem;
1511                         token = match_token(string, nfs_local_lock_tokens,
1512                                         args);
1513                         kfree(string);
1514                         switch (token) {
1515                         case Opt_local_lock_all:
1516                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1517                                                NFS_MOUNT_LOCAL_FCNTL);
1518                                 break;
1519                         case Opt_local_lock_flock:
1520                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1521                                 break;
1522                         case Opt_local_lock_posix:
1523                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1524                                 break;
1525                         case Opt_local_lock_none:
1526                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1527                                                 NFS_MOUNT_LOCAL_FCNTL);
1528                                 break;
1529                         default:
1530                                 dfprintk(MOUNT, "NFS:   invalid "
1531                                                 "local_lock argument\n");
1532                                 return 0;
1533                         };
1534                         break;
1535
1536                 /*
1537                  * Special options
1538                  */
1539                 case Opt_sloppy:
1540                         sloppy = 1;
1541                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1542                         break;
1543                 case Opt_userspace:
1544                 case Opt_deprecated:
1545                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1546                                         "'%s'\n", p);
1547                         break;
1548
1549                 default:
1550                         invalid_option = 1;
1551                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1552                                         "'%s'\n", p);
1553                 }
1554         }
1555
1556         if (!sloppy && invalid_option)
1557                 return 0;
1558
1559         if (mnt->minorversion && mnt->version != 4)
1560                 goto out_minorversion_mismatch;
1561
1562         if (mnt->options & NFS_OPTION_MIGRATION &&
1563             mnt->version != 4 && mnt->minorversion != 0)
1564                 goto out_migration_misuse;
1565
1566         /*
1567          * verify that any proto=/mountproto= options match the address
1568          * families in the addr=/mountaddr= options.
1569          */
1570         if (protofamily != AF_UNSPEC &&
1571             protofamily != mnt->nfs_server.address.ss_family)
1572                 goto out_proto_mismatch;
1573
1574         if (mountfamily != AF_UNSPEC) {
1575                 if (mnt->mount_server.addrlen) {
1576                         if (mountfamily != mnt->mount_server.address.ss_family)
1577                                 goto out_mountproto_mismatch;
1578                 } else {
1579                         if (mountfamily != mnt->nfs_server.address.ss_family)
1580                                 goto out_mountproto_mismatch;
1581                 }
1582         }
1583
1584         return 1;
1585
1586 out_mountproto_mismatch:
1587         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1588                          "option\n");
1589         return 0;
1590 out_proto_mismatch:
1591         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1592         return 0;
1593 out_invalid_address:
1594         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1595         return 0;
1596 out_invalid_value:
1597         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1598         return 0;
1599 out_minorversion_mismatch:
1600         printk(KERN_INFO "NFS: mount option vers=%u does not support "
1601                          "minorversion=%u\n", mnt->version, mnt->minorversion);
1602         return 0;
1603 out_migration_misuse:
1604         printk(KERN_INFO
1605                 "NFS: 'migration' not supported for this NFS version\n");
1606         return 0;
1607 out_nomem:
1608         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1609         return 0;
1610 out_security_failure:
1611         free_secdata(secdata);
1612         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1613         return 0;
1614 }
1615
1616 /*
1617  * Select a security flavor for this mount.  The selected flavor
1618  * is planted in args->auth_flavors[0].
1619  *
1620  * Returns 0 on success, -EACCES on failure.
1621  */
1622 static int nfs_select_flavor(struct nfs_parsed_mount_data *args,
1623                               struct nfs_mount_request *request)
1624 {
1625         unsigned int i, count = *(request->auth_flav_len);
1626         rpc_authflavor_t flavor;
1627
1628         /*
1629          * The NFSv2 MNT operation does not return a flavor list.
1630          */
1631         if (args->mount_server.version != NFS_MNT3_VERSION)
1632                 goto out_default;
1633
1634         /*
1635          * Certain releases of Linux's mountd return an empty
1636          * flavor list in some cases.
1637          */
1638         if (count == 0)
1639                 goto out_default;
1640
1641         /*
1642          * If the sec= mount option is used, the specified flavor or AUTH_NULL
1643          * must be in the list returned by the server.
1644          *
1645          * AUTH_NULL has a special meaning when it's in the server list - it
1646          * means that the server will ignore the rpc creds, so any flavor
1647          * can be used.
1648          */
1649         if (args->auth_flavors[0] != RPC_AUTH_MAXFLAVOR) {
1650                 for (i = 0; i < count; i++) {
1651                         if (args->auth_flavors[0] == request->auth_flavs[i] ||
1652                             request->auth_flavs[i] == RPC_AUTH_NULL)
1653                                 goto out;
1654                 }
1655                 dfprintk(MOUNT, "NFS: auth flavor %d not supported by server\n",
1656                         args->auth_flavors[0]);
1657                 goto out_err;
1658         }
1659
1660         /*
1661          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1662          * flavor listed first.  However, some servers list
1663          * AUTH_NULL first.  Avoid ever choosing AUTH_NULL.
1664          */
1665         for (i = 0; i < count; i++) {
1666                 struct rpcsec_gss_info info;
1667
1668                 flavor = request->auth_flavs[i];
1669                 switch (flavor) {
1670                 case RPC_AUTH_UNIX:
1671                         goto out_set;
1672                 case RPC_AUTH_NULL:
1673                         continue;
1674                 default:
1675                         if (rpcauth_get_gssinfo(flavor, &info) == 0)
1676                                 goto out_set;
1677                 }
1678         }
1679
1680         /*
1681          * As a last chance, see if the server list contains AUTH_NULL -
1682          * if it does, use the default flavor.
1683          */
1684         for (i = 0; i < count; i++) {
1685                 if (request->auth_flavs[i] == RPC_AUTH_NULL)
1686                         goto out_default;
1687         }
1688
1689         dfprintk(MOUNT, "NFS: no auth flavors in common with server\n");
1690         goto out_err;
1691
1692 out_default:
1693         /* use default if flavor not already set */
1694         flavor = (args->auth_flavors[0] == RPC_AUTH_MAXFLAVOR) ?
1695                 RPC_AUTH_UNIX : args->auth_flavors[0];
1696 out_set:
1697         args->auth_flavors[0] = flavor;
1698 out:
1699         dfprintk(MOUNT, "NFS: using auth flavor %d\n", args->auth_flavors[0]);
1700         return 0;
1701 out_err:
1702         return -EACCES;
1703 }
1704
1705 /*
1706  * Use the remote server's MOUNT service to request the NFS file handle
1707  * corresponding to the provided path.
1708  */
1709 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1710                              struct nfs_fh *root_fh)
1711 {
1712         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1713         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1714         struct nfs_mount_request request = {
1715                 .sap            = (struct sockaddr *)
1716                                                 &args->mount_server.address,
1717                 .dirpath        = args->nfs_server.export_path,
1718                 .protocol       = args->mount_server.protocol,
1719                 .fh             = root_fh,
1720                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1721                 .auth_flav_len  = &server_authlist_len,
1722                 .auth_flavs     = server_authlist,
1723                 .net            = args->net,
1724         };
1725         int status;
1726
1727         if (args->mount_server.version == 0) {
1728                 switch (args->version) {
1729                         default:
1730                                 args->mount_server.version = NFS_MNT3_VERSION;
1731                                 break;
1732                         case 2:
1733                                 args->mount_server.version = NFS_MNT_VERSION;
1734                 }
1735         }
1736         request.version = args->mount_server.version;
1737
1738         if (args->mount_server.hostname)
1739                 request.hostname = args->mount_server.hostname;
1740         else
1741                 request.hostname = args->nfs_server.hostname;
1742
1743         /*
1744          * Construct the mount server's address.
1745          */
1746         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1747                 memcpy(request.sap, &args->nfs_server.address,
1748                        args->nfs_server.addrlen);
1749                 args->mount_server.addrlen = args->nfs_server.addrlen;
1750         }
1751         request.salen = args->mount_server.addrlen;
1752         nfs_set_port(request.sap, &args->mount_server.port, 0);
1753
1754         /*
1755          * Now ask the mount server to map our export path
1756          * to a file handle.
1757          */
1758         status = nfs_mount(&request);
1759         if (status != 0) {
1760                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1761                                 request.hostname, status);
1762                 return status;
1763         }
1764
1765         return nfs_select_flavor(args, &request);
1766 }
1767
1768 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1769                              struct nfs_mount_info *mount_info,
1770                              struct nfs_subversion *nfs_mod)
1771 {
1772         int status;
1773         struct nfs_server *server;
1774
1775         if (mount_info->parsed->need_mount) {
1776                 status = nfs_request_mount(mount_info->parsed, mount_info->mntfh);
1777                 if (status)
1778                         return ERR_PTR(status);
1779         }
1780
1781         /* Get a volume representation */
1782         server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1783         if (IS_ERR(server))
1784                 return ERR_CAST(server);
1785
1786         return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1787 }
1788 EXPORT_SYMBOL_GPL(nfs_try_mount);
1789
1790 /*
1791  * Split "dev_name" into "hostname:export_path".
1792  *
1793  * The leftmost colon demarks the split between the server's hostname
1794  * and the export path.  If the hostname starts with a left square
1795  * bracket, then it may contain colons.
1796  *
1797  * Note: caller frees hostname and export path, even on error.
1798  */
1799 static int nfs_parse_devname(const char *dev_name,
1800                              char **hostname, size_t maxnamlen,
1801                              char **export_path, size_t maxpathlen)
1802 {
1803         size_t len;
1804         char *end;
1805
1806         /* Is the host name protected with square brakcets? */
1807         if (*dev_name == '[') {
1808                 end = strchr(++dev_name, ']');
1809                 if (end == NULL || end[1] != ':')
1810                         goto out_bad_devname;
1811
1812                 len = end - dev_name;
1813                 end++;
1814         } else {
1815                 char *comma;
1816
1817                 end = strchr(dev_name, ':');
1818                 if (end == NULL)
1819                         goto out_bad_devname;
1820                 len = end - dev_name;
1821
1822                 /* kill possible hostname list: not supported */
1823                 comma = strchr(dev_name, ',');
1824                 if (comma != NULL && comma < end)
1825                         *comma = 0;
1826         }
1827
1828         if (len > maxnamlen)
1829                 goto out_hostname;
1830
1831         /* N.B. caller will free nfs_server.hostname in all cases */
1832         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1833         if (*hostname == NULL)
1834                 goto out_nomem;
1835         len = strlen(++end);
1836         if (len > maxpathlen)
1837                 goto out_path;
1838         *export_path = kstrndup(end, len, GFP_KERNEL);
1839         if (!*export_path)
1840                 goto out_nomem;
1841
1842         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1843         return 0;
1844
1845 out_bad_devname:
1846         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1847         return -EINVAL;
1848
1849 out_nomem:
1850         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1851         return -ENOMEM;
1852
1853 out_hostname:
1854         dfprintk(MOUNT, "NFS: server hostname too long\n");
1855         return -ENAMETOOLONG;
1856
1857 out_path:
1858         dfprintk(MOUNT, "NFS: export pathname too long\n");
1859         return -ENAMETOOLONG;
1860 }
1861
1862 /*
1863  * Validate the NFS2/NFS3 mount data
1864  * - fills in the mount root filehandle
1865  *
1866  * For option strings, user space handles the following behaviors:
1867  *
1868  * + DNS: mapping server host name to IP address ("addr=" option)
1869  *
1870  * + failure mode: how to behave if a mount request can't be handled
1871  *   immediately ("fg/bg" option)
1872  *
1873  * + retry: how often to retry a mount request ("retry=" option)
1874  *
1875  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1876  *   mountproto=tcp after mountproto=udp, and so on
1877  */
1878 static int nfs23_validate_mount_data(void *options,
1879                                      struct nfs_parsed_mount_data *args,
1880                                      struct nfs_fh *mntfh,
1881                                      const char *dev_name)
1882 {
1883         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1884         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1885
1886         if (data == NULL)
1887                 goto out_no_data;
1888
1889         args->version = NFS_DEFAULT_VERSION;
1890         switch (data->version) {
1891         case 1:
1892                 data->namlen = 0;
1893         case 2:
1894                 data->bsize = 0;
1895         case 3:
1896                 if (data->flags & NFS_MOUNT_VER3)
1897                         goto out_no_v3;
1898                 data->root.size = NFS2_FHSIZE;
1899                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1900         case 4:
1901                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1902                         goto out_no_sec;
1903         case 5:
1904                 memset(data->context, 0, sizeof(data->context));
1905         case 6:
1906                 if (data->flags & NFS_MOUNT_VER3) {
1907                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1908                                 goto out_invalid_fh;
1909                         mntfh->size = data->root.size;
1910                         args->version = 3;
1911                 } else {
1912                         mntfh->size = NFS2_FHSIZE;
1913                         args->version = 2;
1914                 }
1915
1916
1917                 memcpy(mntfh->data, data->root.data, mntfh->size);
1918                 if (mntfh->size < sizeof(mntfh->data))
1919                         memset(mntfh->data + mntfh->size, 0,
1920                                sizeof(mntfh->data) - mntfh->size);
1921
1922                 /*
1923                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1924                  * can deal with.
1925                  */
1926                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1927                 args->flags             |= NFS_MOUNT_LEGACY_INTERFACE;
1928                 args->rsize             = data->rsize;
1929                 args->wsize             = data->wsize;
1930                 args->timeo             = data->timeo;
1931                 args->retrans           = data->retrans;
1932                 args->acregmin          = data->acregmin;
1933                 args->acregmax          = data->acregmax;
1934                 args->acdirmin          = data->acdirmin;
1935                 args->acdirmax          = data->acdirmax;
1936                 args->need_mount        = false;
1937
1938                 memcpy(sap, &data->addr, sizeof(data->addr));
1939                 args->nfs_server.addrlen = sizeof(data->addr);
1940                 args->nfs_server.port = ntohs(data->addr.sin_port);
1941                 if (!nfs_verify_server_address(sap))
1942                         goto out_no_address;
1943
1944                 if (!(data->flags & NFS_MOUNT_TCP))
1945                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1946                 /* N.B. caller will free nfs_server.hostname in all cases */
1947                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1948                 args->namlen            = data->namlen;
1949                 args->bsize             = data->bsize;
1950
1951                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1952                         args->auth_flavors[0] = data->pseudoflavor;
1953                 if (!args->nfs_server.hostname)
1954                         goto out_nomem;
1955
1956                 if (!(data->flags & NFS_MOUNT_NONLM))
1957                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1958                                          NFS_MOUNT_LOCAL_FCNTL);
1959                 else
1960                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1961                                         NFS_MOUNT_LOCAL_FCNTL);
1962                 /*
1963                  * The legacy version 6 binary mount data from userspace has a
1964                  * field used only to transport selinux information into the
1965                  * the kernel.  To continue to support that functionality we
1966                  * have a touch of selinux knowledge here in the NFS code. The
1967                  * userspace code converted context=blah to just blah so we are
1968                  * converting back to the full string selinux understands.
1969                  */
1970                 if (data->context[0]){
1971 #ifdef CONFIG_SECURITY_SELINUX
1972                         int rc;
1973                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1974                         if (!opts_str)
1975                                 return -ENOMEM;
1976                         strcpy(opts_str, "context=");
1977                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1978                         strcat(opts_str, &data->context[0]);
1979                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1980                         kfree(opts_str);
1981                         if (rc)
1982                                 return rc;
1983 #else
1984                         return -EINVAL;
1985 #endif
1986                 }
1987
1988                 break;
1989         default:
1990                 return NFS_TEXT_DATA;
1991         }
1992
1993 #if !IS_ENABLED(CONFIG_NFS_V3)
1994         if (args->version == 3)
1995                 goto out_v3_not_compiled;
1996 #endif /* !CONFIG_NFS_V3 */
1997
1998         return 0;
1999
2000 out_no_data:
2001         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2002         return -EINVAL;
2003
2004 out_no_v3:
2005         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2006                  data->version);
2007         return -EINVAL;
2008
2009 out_no_sec:
2010         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2011         return -EINVAL;
2012
2013 #if !IS_ENABLED(CONFIG_NFS_V3)
2014 out_v3_not_compiled:
2015         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
2016         return -EPROTONOSUPPORT;
2017 #endif /* !CONFIG_NFS_V3 */
2018
2019 out_nomem:
2020         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2021         return -ENOMEM;
2022
2023 out_no_address:
2024         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2025         return -EINVAL;
2026
2027 out_invalid_fh:
2028         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2029         return -EINVAL;
2030 }
2031
2032 #if IS_ENABLED(CONFIG_NFS_V4)
2033 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2034                                    void *options,
2035                                    struct nfs_parsed_mount_data *args,
2036                                    struct nfs_fh *mntfh,
2037                                    const char *dev_name)
2038 {
2039         if (fs_type == &nfs_fs_type)
2040                 return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2041         return nfs4_validate_mount_data(options, args, dev_name);
2042 }
2043 #else
2044 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2045                                    void *options,
2046                                    struct nfs_parsed_mount_data *args,
2047                                    struct nfs_fh *mntfh,
2048                                    const char *dev_name)
2049 {
2050         return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2051 }
2052 #endif
2053
2054 static int nfs_validate_text_mount_data(void *options,
2055                                         struct nfs_parsed_mount_data *args,
2056                                         const char *dev_name)
2057 {
2058         int port = 0;
2059         int max_namelen = PAGE_SIZE;
2060         int max_pathlen = NFS_MAXPATHLEN;
2061         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2062
2063         if (nfs_parse_mount_options((char *)options, args) == 0)
2064                 return -EINVAL;
2065
2066         if (!nfs_verify_server_address(sap))
2067                 goto out_no_address;
2068
2069         if (args->version == 4) {
2070 #if IS_ENABLED(CONFIG_NFS_V4)
2071                 port = NFS_PORT;
2072                 max_namelen = NFS4_MAXNAMLEN;
2073                 max_pathlen = NFS4_MAXPATHLEN;
2074                 nfs_validate_transport_protocol(args);
2075                 nfs4_validate_mount_flags(args);
2076 #else
2077                 goto out_v4_not_compiled;
2078 #endif /* CONFIG_NFS_V4 */
2079         } else
2080                 nfs_set_mount_transport_protocol(args);
2081
2082         nfs_set_port(sap, &args->nfs_server.port, port);
2083
2084         if (args->auth_flavor_len > 1)
2085                 goto out_bad_auth;
2086
2087         return nfs_parse_devname(dev_name,
2088                                    &args->nfs_server.hostname,
2089                                    max_namelen,
2090                                    &args->nfs_server.export_path,
2091                                    max_pathlen);
2092
2093 #if !IS_ENABLED(CONFIG_NFS_V4)
2094 out_v4_not_compiled:
2095         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2096         return -EPROTONOSUPPORT;
2097 #endif /* !CONFIG_NFS_V4 */
2098
2099 out_no_address:
2100         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2101         return -EINVAL;
2102
2103 out_bad_auth:
2104         dfprintk(MOUNT, "NFS: Too many RPC auth flavours specified\n");
2105         return -EINVAL;
2106 }
2107
2108 static int
2109 nfs_compare_remount_data(struct nfs_server *nfss,
2110                          struct nfs_parsed_mount_data *data)
2111 {
2112         if (data->flags != nfss->flags ||
2113             data->rsize != nfss->rsize ||
2114             data->wsize != nfss->wsize ||
2115             data->retrans != nfss->client->cl_timeout->to_retries ||
2116             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
2117             data->acregmin != nfss->acregmin / HZ ||
2118             data->acregmax != nfss->acregmax / HZ ||
2119             data->acdirmin != nfss->acdirmin / HZ ||
2120             data->acdirmax != nfss->acdirmax / HZ ||
2121             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2122             data->nfs_server.port != nfss->port ||
2123             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2124             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2125                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
2126                 return -EINVAL;
2127
2128         return 0;
2129 }
2130
2131 int
2132 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2133 {
2134         int error;
2135         struct nfs_server *nfss = sb->s_fs_info;
2136         struct nfs_parsed_mount_data *data;
2137         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2138         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2139         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2140
2141         /*
2142          * Userspace mount programs that send binary options generally send
2143          * them populated with default values. We have no way to know which
2144          * ones were explicitly specified. Fall back to legacy behavior and
2145          * just return success.
2146          */
2147         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2148             (nfsvers <= 3 && (!options || (options->version >= 1 &&
2149                                            options->version <= 6))))
2150                 return 0;
2151
2152         data = kzalloc(sizeof(*data), GFP_KERNEL);
2153         if (data == NULL)
2154                 return -ENOMEM;
2155
2156         /* fill out struct with values from existing mount */
2157         data->flags = nfss->flags;
2158         data->rsize = nfss->rsize;
2159         data->wsize = nfss->wsize;
2160         data->retrans = nfss->client->cl_timeout->to_retries;
2161         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
2162         data->acregmin = nfss->acregmin / HZ;
2163         data->acregmax = nfss->acregmax / HZ;
2164         data->acdirmin = nfss->acdirmin / HZ;
2165         data->acdirmax = nfss->acdirmax / HZ;
2166         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2167         data->nfs_server.port = nfss->port;
2168         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2169         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2170                 data->nfs_server.addrlen);
2171
2172         /* overwrite those values with any that were specified */
2173         error = nfs_parse_mount_options((char *)options, data);
2174         if (error < 0)
2175                 goto out;
2176
2177         /*
2178          * noac is a special case. It implies -o sync, but that's not
2179          * necessarily reflected in the mtab options. do_remount_sb
2180          * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2181          * remount options, so we have to explicitly reset it.
2182          */
2183         if (data->flags & NFS_MOUNT_NOAC)
2184                 *flags |= MS_SYNCHRONOUS;
2185
2186         /* compare new mount options with old ones */
2187         error = nfs_compare_remount_data(nfss, data);
2188 out:
2189         kfree(data);
2190         return error;
2191 }
2192 EXPORT_SYMBOL_GPL(nfs_remount);
2193
2194 /*
2195  * Initialise the common bits of the superblock
2196  */
2197 inline void nfs_initialise_sb(struct super_block *sb)
2198 {
2199         struct nfs_server *server = NFS_SB(sb);
2200
2201         sb->s_magic = NFS_SUPER_MAGIC;
2202
2203         /* We probably want something more informative here */
2204         snprintf(sb->s_id, sizeof(sb->s_id),
2205                  "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2206
2207         if (sb->s_blocksize == 0)
2208                 sb->s_blocksize = nfs_block_bits(server->wsize,
2209                                                  &sb->s_blocksize_bits);
2210
2211         sb->s_bdi = &server->backing_dev_info;
2212
2213         nfs_super_set_maxbytes(sb, server->maxfilesize);
2214 }
2215
2216 /*
2217  * Finish setting up an NFS2/3 superblock
2218  */
2219 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2220 {
2221         struct nfs_parsed_mount_data *data = mount_info->parsed;
2222         struct nfs_server *server = NFS_SB(sb);
2223
2224         sb->s_blocksize_bits = 0;
2225         sb->s_blocksize = 0;
2226         sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2227         sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2228         if (data && data->bsize)
2229                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2230
2231         if (server->nfs_client->rpc_ops->version != 2) {
2232                 /* The VFS shouldn't apply the umask to mode bits. We will do
2233                  * so ourselves when necessary.
2234                  */
2235                 sb->s_flags |= MS_POSIXACL;
2236                 sb->s_time_gran = 1;
2237         }
2238
2239         nfs_initialise_sb(sb);
2240 }
2241 EXPORT_SYMBOL_GPL(nfs_fill_super);
2242
2243 /*
2244  * Finish setting up a cloned NFS2/3/4 superblock
2245  */
2246 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2247 {
2248         const struct super_block *old_sb = mount_info->cloned->sb;
2249         struct nfs_server *server = NFS_SB(sb);
2250
2251         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2252         sb->s_blocksize = old_sb->s_blocksize;
2253         sb->s_maxbytes = old_sb->s_maxbytes;
2254         sb->s_xattr = old_sb->s_xattr;
2255         sb->s_op = old_sb->s_op;
2256         sb->s_time_gran = 1;
2257
2258         if (server->nfs_client->rpc_ops->version != 2) {
2259                 /* The VFS shouldn't apply the umask to mode bits. We will do
2260                  * so ourselves when necessary.
2261                  */
2262                 sb->s_flags |= MS_POSIXACL;
2263         }
2264
2265         nfs_initialise_sb(sb);
2266 }
2267
2268 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2269 {
2270         const struct nfs_server *a = s->s_fs_info;
2271         const struct rpc_clnt *clnt_a = a->client;
2272         const struct rpc_clnt *clnt_b = b->client;
2273
2274         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2275                 goto Ebusy;
2276         if (a->nfs_client != b->nfs_client)
2277                 goto Ebusy;
2278         if (a->flags != b->flags)
2279                 goto Ebusy;
2280         if (a->wsize != b->wsize)
2281                 goto Ebusy;
2282         if (a->rsize != b->rsize)
2283                 goto Ebusy;
2284         if (a->acregmin != b->acregmin)
2285                 goto Ebusy;
2286         if (a->acregmax != b->acregmax)
2287                 goto Ebusy;
2288         if (a->acdirmin != b->acdirmin)
2289                 goto Ebusy;
2290         if (a->acdirmax != b->acdirmax)
2291                 goto Ebusy;
2292         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2293                 goto Ebusy;
2294         return 1;
2295 Ebusy:
2296         return 0;
2297 }
2298
2299 struct nfs_sb_mountdata {
2300         struct nfs_server *server;
2301         int mntflags;
2302 };
2303
2304 static int nfs_set_super(struct super_block *s, void *data)
2305 {
2306         struct nfs_sb_mountdata *sb_mntdata = data;
2307         struct nfs_server *server = sb_mntdata->server;
2308         int ret;
2309
2310         s->s_flags = sb_mntdata->mntflags;
2311         s->s_fs_info = server;
2312         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2313         ret = set_anon_super(s, server);
2314         if (ret == 0)
2315                 server->s_dev = s->s_dev;
2316         return ret;
2317 }
2318
2319 static int nfs_compare_super_address(struct nfs_server *server1,
2320                                      struct nfs_server *server2)
2321 {
2322         struct sockaddr *sap1, *sap2;
2323
2324         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2325         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2326
2327         if (sap1->sa_family != sap2->sa_family)
2328                 return 0;
2329
2330         switch (sap1->sa_family) {
2331         case AF_INET: {
2332                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2333                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2334                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2335                         return 0;
2336                 if (sin1->sin_port != sin2->sin_port)
2337                         return 0;
2338                 break;
2339         }
2340         case AF_INET6: {
2341                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2342                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2343                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2344                         return 0;
2345                 if (sin1->sin6_port != sin2->sin6_port)
2346                         return 0;
2347                 break;
2348         }
2349         default:
2350                 return 0;
2351         }
2352
2353         return 1;
2354 }
2355
2356 static int nfs_compare_super(struct super_block *sb, void *data)
2357 {
2358         struct nfs_sb_mountdata *sb_mntdata = data;
2359         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2360         int mntflags = sb_mntdata->mntflags;
2361
2362         if (!nfs_compare_super_address(old, server))
2363                 return 0;
2364         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2365         if (old->flags & NFS_MOUNT_UNSHARED)
2366                 return 0;
2367         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2368                 return 0;
2369         return nfs_compare_mount_options(sb, server, mntflags);
2370 }
2371
2372 #ifdef CONFIG_NFS_FSCACHE
2373 static void nfs_get_cache_cookie(struct super_block *sb,
2374                                  struct nfs_parsed_mount_data *parsed,
2375                                  struct nfs_clone_mount *cloned)
2376 {
2377         struct nfs_server *nfss = NFS_SB(sb);
2378         char *uniq = NULL;
2379         int ulen = 0;
2380
2381         nfss->fscache_key = NULL;
2382         nfss->fscache = NULL;
2383
2384         if (parsed) {
2385                 if (!(parsed->options & NFS_OPTION_FSCACHE))
2386                         return;
2387                 if (parsed->fscache_uniq) {
2388                         uniq = parsed->fscache_uniq;
2389                         ulen = strlen(parsed->fscache_uniq);
2390                 }
2391         } else if (cloned) {
2392                 struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2393                 if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2394                         return;
2395                 if (mnt_s->fscache_key) {
2396                         uniq = mnt_s->fscache_key->key.uniquifier;
2397                         ulen = mnt_s->fscache_key->key.uniq_len;
2398                 };
2399         } else
2400                 return;
2401
2402         nfs_fscache_get_super_cookie(sb, uniq, ulen);
2403 }
2404 #else
2405 static void nfs_get_cache_cookie(struct super_block *sb,
2406                                  struct nfs_parsed_mount_data *parsed,
2407                                  struct nfs_clone_mount *cloned)
2408 {
2409 }
2410 #endif
2411
2412 static int nfs_bdi_register(struct nfs_server *server)
2413 {
2414         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2415 }
2416
2417 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2418                         struct nfs_mount_info *mount_info)
2419 {
2420         return security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts,
2421                                                                 0, NULL);
2422 }
2423 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2424
2425 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2426                           struct nfs_mount_info *mount_info)
2427 {
2428         /* clone any lsm security options from the parent to the new sb */
2429         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2430                 return -ESTALE;
2431         return security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2432 }
2433 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2434
2435 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2436                                    int flags, const char *dev_name,
2437                                    struct nfs_mount_info *mount_info,
2438                                    struct nfs_subversion *nfs_mod)
2439 {
2440         struct super_block *s;
2441         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2442         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2443         struct nfs_sb_mountdata sb_mntdata = {
2444                 .mntflags = flags,
2445                 .server = server,
2446         };
2447         int error;
2448
2449         if (server->flags & NFS_MOUNT_UNSHARED)
2450                 compare_super = NULL;
2451
2452         /* -o noac implies -o sync */
2453         if (server->flags & NFS_MOUNT_NOAC)
2454                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2455
2456         /* Get a superblock - note that we may end up sharing one that already exists */
2457         s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2458         if (IS_ERR(s)) {
2459                 mntroot = ERR_CAST(s);
2460                 goto out_err_nosb;
2461         }
2462
2463         if (s->s_fs_info != server) {
2464                 nfs_free_server(server);
2465                 server = NULL;
2466         } else {
2467                 error = nfs_bdi_register(server);
2468                 if (error) {
2469                         mntroot = ERR_PTR(error);
2470                         goto error_splat_bdi;
2471                 }
2472         }
2473
2474         if (!s->s_root) {
2475                 /* initial superblock/root creation */
2476                 mount_info->fill_super(s, mount_info);
2477                 nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2478         }
2479
2480         mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2481         if (IS_ERR(mntroot))
2482                 goto error_splat_super;
2483
2484         error = mount_info->set_security(s, mntroot, mount_info);
2485         if (error)
2486                 goto error_splat_root;
2487
2488         s->s_flags |= MS_ACTIVE;
2489
2490 out:
2491         return mntroot;
2492
2493 out_err_nosb:
2494         nfs_free_server(server);
2495         goto out;
2496
2497 error_splat_root:
2498         dput(mntroot);
2499         mntroot = ERR_PTR(error);
2500 error_splat_super:
2501         if (server && !s->s_root)
2502                 bdi_unregister(&server->backing_dev_info);
2503 error_splat_bdi:
2504         deactivate_locked_super(s);
2505         goto out;
2506 }
2507 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2508
2509 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2510         int flags, const char *dev_name, void *raw_data)
2511 {
2512         struct nfs_mount_info mount_info = {
2513                 .fill_super = nfs_fill_super,
2514                 .set_security = nfs_set_sb_security,
2515         };
2516         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2517         struct nfs_subversion *nfs_mod;
2518         int error;
2519
2520         mount_info.parsed = nfs_alloc_parsed_mount_data();
2521         mount_info.mntfh = nfs_alloc_fhandle();
2522         if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2523                 goto out;
2524
2525         /* Validate the mount data */
2526         error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2527         if (error == NFS_TEXT_DATA)
2528                 error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2529         if (error < 0) {
2530                 mntroot = ERR_PTR(error);
2531                 goto out;
2532         }
2533
2534         nfs_mod = get_nfs_version(mount_info.parsed->version);
2535         if (IS_ERR(nfs_mod)) {
2536                 mntroot = ERR_CAST(nfs_mod);
2537                 goto out;
2538         }
2539
2540         mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2541
2542         put_nfs_version(nfs_mod);
2543 out:
2544         nfs_free_parsed_mount_data(mount_info.parsed);
2545         nfs_free_fhandle(mount_info.mntfh);
2546         return mntroot;
2547 }
2548 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2549
2550 /*
2551  * Ensure that we unregister the bdi before kill_anon_super
2552  * releases the device name
2553  */
2554 void nfs_put_super(struct super_block *s)
2555 {
2556         struct nfs_server *server = NFS_SB(s);
2557
2558         bdi_unregister(&server->backing_dev_info);
2559 }
2560 EXPORT_SYMBOL_GPL(nfs_put_super);
2561
2562 /*
2563  * Destroy an NFS2/3 superblock
2564  */
2565 void nfs_kill_super(struct super_block *s)
2566 {
2567         struct nfs_server *server = NFS_SB(s);
2568
2569         kill_anon_super(s);
2570         nfs_fscache_release_super_cookie(s);
2571         nfs_free_server(server);
2572 }
2573 EXPORT_SYMBOL_GPL(nfs_kill_super);
2574
2575 /*
2576  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2577  */
2578 static struct dentry *
2579 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2580                 const char *dev_name, void *raw_data)
2581 {
2582         struct nfs_clone_mount *data = raw_data;
2583         struct nfs_mount_info mount_info = {
2584                 .fill_super = nfs_clone_super,
2585                 .set_security = nfs_clone_sb_security,
2586                 .cloned = data,
2587         };
2588         struct nfs_server *server;
2589         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2590         struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2591
2592         dprintk("--> nfs_xdev_mount()\n");
2593
2594         mount_info.mntfh = mount_info.cloned->fh;
2595
2596         /* create a new volume representation */
2597         server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2598
2599         if (IS_ERR(server))
2600                 mntroot = ERR_CAST(server);
2601         else
2602                 mntroot = nfs_fs_mount_common(server, flags,
2603                                 dev_name, &mount_info, nfs_mod);
2604
2605         dprintk("<-- nfs_xdev_mount() = %ld\n",
2606                         IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2607         return mntroot;
2608 }
2609
2610 #if IS_ENABLED(CONFIG_NFS_V4)
2611
2612 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2613 {
2614         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2615                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2616 }
2617
2618 /*
2619  * Validate NFSv4 mount options
2620  */
2621 static int nfs4_validate_mount_data(void *options,
2622                                     struct nfs_parsed_mount_data *args,
2623                                     const char *dev_name)
2624 {
2625         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2626         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2627         char *c;
2628
2629         if (data == NULL)
2630                 goto out_no_data;
2631
2632         args->version = 4;
2633
2634         switch (data->version) {
2635         case 1:
2636                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2637                         goto out_no_address;
2638                 if (data->host_addrlen == 0)
2639                         goto out_no_address;
2640                 args->nfs_server.addrlen = data->host_addrlen;
2641                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2642                         return -EFAULT;
2643                 if (!nfs_verify_server_address(sap))
2644                         goto out_no_address;
2645                 args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2646
2647                 if (data->auth_flavourlen) {
2648                         if (data->auth_flavourlen > 1)
2649                                 goto out_inval_auth;
2650                         if (copy_from_user(&args->auth_flavors[0],
2651                                            data->auth_flavours,
2652                                            sizeof(args->auth_flavors[0])))
2653                                 return -EFAULT;
2654                 }
2655
2656                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2657                 if (IS_ERR(c))
2658                         return PTR_ERR(c);
2659                 args->nfs_server.hostname = c;
2660
2661                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2662                 if (IS_ERR(c))
2663                         return PTR_ERR(c);
2664                 args->nfs_server.export_path = c;
2665                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2666
2667                 c = strndup_user(data->client_addr.data, 16);
2668                 if (IS_ERR(c))
2669                         return PTR_ERR(c);
2670                 args->client_address = c;
2671
2672                 /*
2673                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2674                  * can deal with.
2675                  */
2676
2677                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2678                 args->rsize     = data->rsize;
2679                 args->wsize     = data->wsize;
2680                 args->timeo     = data->timeo;
2681                 args->retrans   = data->retrans;
2682                 args->acregmin  = data->acregmin;
2683                 args->acregmax  = data->acregmax;
2684                 args->acdirmin  = data->acdirmin;
2685                 args->acdirmax  = data->acdirmax;
2686                 args->nfs_server.protocol = data->proto;
2687                 nfs_validate_transport_protocol(args);
2688
2689                 break;
2690         default:
2691                 return NFS_TEXT_DATA;
2692         }
2693
2694         return 0;
2695
2696 out_no_data:
2697         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2698         return -EINVAL;
2699
2700 out_inval_auth:
2701         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2702                  data->auth_flavourlen);
2703         return -EINVAL;
2704
2705 out_no_address:
2706         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2707         return -EINVAL;
2708 }
2709
2710 /*
2711  * NFS v4 module parameters need to stay in the
2712  * NFS client for backwards compatibility
2713  */
2714 unsigned int nfs_callback_set_tcpport;
2715 unsigned short nfs_callback_tcpport;
2716 /* Default cache timeout is 10 minutes */
2717 unsigned int nfs_idmap_cache_timeout = 600;
2718 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2719 bool nfs4_disable_idmapping = true;
2720 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2721 unsigned short send_implementation_id = 1;
2722 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2723
2724 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2725 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
2726 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2727 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2728 EXPORT_SYMBOL_GPL(max_session_slots);
2729 EXPORT_SYMBOL_GPL(send_implementation_id);
2730 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2731
2732 #define NFS_CALLBACK_MAXPORTNR (65535U)
2733
2734 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2735 {
2736         unsigned long num;
2737         int ret;
2738
2739         if (!val)
2740                 return -EINVAL;
2741         ret = kstrtoul(val, 0, &num);
2742         if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2743                 return -EINVAL;
2744         *((unsigned int *)kp->arg) = num;
2745         return 0;
2746 }
2747 static struct kernel_param_ops param_ops_portnr = {
2748         .set = param_set_portnr,
2749         .get = param_get_uint,
2750 };
2751 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2752
2753 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2754 module_param(nfs_idmap_cache_timeout, int, 0644);
2755 module_param(nfs4_disable_idmapping, bool, 0644);
2756 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2757                         NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2758 MODULE_PARM_DESC(nfs4_disable_idmapping,
2759                 "Turn off NFSv4 idmapping when using 'sec=sys'");
2760 module_param(max_session_slots, ushort, 0644);
2761 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2762                 "requests the client will negotiate");
2763 module_param(send_implementation_id, ushort, 0644);
2764 MODULE_PARM_DESC(send_implementation_id,
2765                 "Send implementation ID with NFSv4.1 exchange_id");
2766 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2767
2768 #endif /* CONFIG_NFS_V4 */